func()

in model/textparse/openmetricsparse.go [226:361]

• 129 lines of code
• 41 McCabe index (conditional complexity)

func (p *OpenMetricsParser) Next() (Entry, error) {
	var err error

	p.start = p.l.i
	p.offsets = p.offsets[:0]
	p.eOffsets = p.eOffsets[:0]
	p.exemplar = p.exemplar[:0]
	p.exemplarVal = 0
	p.hasExemplarTs = false

	switch t := p.nextToken(); t {
	case tEOFWord:
		if t := p.nextToken(); t != tEOF {
			return EntryInvalid, errors.New("unexpected data after # EOF")
		}
		return EntryInvalid, io.EOF
	case tEOF:
		return EntryInvalid, errors.New("data does not end with # EOF")
	case tHelp, tType, tUnit:
		switch t2 := p.nextToken(); t2 {
		case tMName:
			p.offsets = append(p.offsets, p.l.start, p.l.i)
		default:
			return EntryInvalid, p.parseError("expected metric name after "+t.String(), t2)
		}
		switch t2 := p.nextToken(); t2 {
		case tText:
			if len(p.l.buf()) > 1 {
				p.text = p.l.buf()[1 : len(p.l.buf())-1]
			} else {
				p.text = []byte{}
			}
		default:
			return EntryInvalid, fmt.Errorf("expected text in %s", t.String())
		}
		switch t {
		case tType:
			switch s := yoloString(p.text); s {
			case "counter":
				p.mtype = MetricTypeCounter
			case "gauge":
				p.mtype = MetricTypeGauge
			case "histogram":
				p.mtype = MetricTypeHistogram
			case "gaugehistogram":
				p.mtype = MetricTypeGaugeHistogram
			case "summary":
				p.mtype = MetricTypeSummary
			case "info":
				p.mtype = MetricTypeInfo
			case "stateset":
				p.mtype = MetricTypeStateset
			case "unknown":
				p.mtype = MetricTypeUnknown
			default:
				return EntryInvalid, fmt.Errorf("invalid metric type %q", s)
			}
		case tHelp:
			if !utf8.Valid(p.text) {
				return EntryInvalid, fmt.Errorf("help text %q is not a valid utf8 string", p.text)
			}
		}
		switch t {
		case tHelp:
			return EntryHelp, nil
		case tType:
			return EntryType, nil
		case tUnit:
			m := yoloString(p.l.b[p.offsets[0]:p.offsets[1]])
			u := yoloString(p.text)
			if len(u) > 0 {
				if !strings.HasSuffix(m, u) || len(m) < len(u)+1 || p.l.b[p.offsets[1]-len(u)-1] != '_' {
					return EntryInvalid, fmt.Errorf("unit %q not a suffix of metric %q", u, m)
				}
			}
			return EntryUnit, nil
		}

	case tMName:
		p.offsets = append(p.offsets, p.l.i)
		p.series = p.l.b[p.start:p.l.i]

		t2 := p.nextToken()
		if t2 == tBraceOpen {
			p.offsets, err = p.parseLVals(p.offsets)
			if err != nil {
				return EntryInvalid, err
			}
			p.series = p.l.b[p.start:p.l.i]
			t2 = p.nextToken()
		}
		p.val, err = p.getFloatValue(t2, "metric")
		if err != nil {
			return EntryInvalid, err
		}

		p.hasTS = false
		switch t2 := p.nextToken(); t2 {
		case tEOF:
			return EntryInvalid, errors.New("data does not end with # EOF")
		case tLinebreak:
			break
		case tComment:
			if err := p.parseComment(); err != nil {
				return EntryInvalid, err
			}
		case tTimestamp:
			p.hasTS = true
			var ts float64
			// A float is enough to hold what we need for millisecond resolution.
			if ts, err = parseFloat(yoloString(p.l.buf()[1:])); err != nil {
				return EntryInvalid, fmt.Errorf("%v while parsing: %q", err, p.l.b[p.start:p.l.i])
			}
			if math.IsNaN(ts) || math.IsInf(ts, 0) {
				return EntryInvalid, fmt.Errorf("invalid timestamp %f", ts)
			}
			p.ts = int64(ts * 1000)
			switch t3 := p.nextToken(); t3 {
			case tLinebreak:
			case tComment:
				if err := p.parseComment(); err != nil {
					return EntryInvalid, err
				}
			default:
				return EntryInvalid, p.parseError("expected next entry after timestamp", t3)
			}
		default:
			return EntryInvalid, p.parseError("expected timestamp or # symbol", t2)
		}
		return EntrySeries, nil

	default:
		err = p.parseError("expected a valid start token", t)
	}
	return EntryInvalid, err
}